Add custom scenarios to the API

[ForgettableUsername]

No description provided.

[0dinD]

This is something I'd like to do in the future, but my time is limited so it's probably not happening soon. See also: https://uhccore.zerodind.net/faq/#can-i-add-my-own-custom-scenarios

Also, this repository is not used for active development of UhcCore anymore (the original owner is no longer maintaining it), I just happened to see your issue. In the future, feel free to report issues at https://gitlab.com/uhccore/uhccore, or on the Discord server :)